clear;

Hd=filtr1;
x=randn(1,1000);
y=filter(Hd,x);

Sx = fft(x);
Sy = fft(y);
plot([x;y]')
Sx = 20*log10(abs(fft(x)));
Sy = 20*log10(abs(fft(y)));
plot([Sx;Sy]');
